Plastic in Oceans: Should We Bury More Of Our Waste?
The US has sent 70% of its recyclables to China for years, but China has mismanaged it. China is now refusing most waste and recycling imports. How could it be managed better locally?
More than 70% of the Earth's surface is covered in ocean, and in June every year The National Oceanic and Atmospheric Administration (NOAA) celebrates National Ocean Month. This year they have shared several inspiring pieces about the depth, mystery, and vibrancy of our world's oceans.
However, there are now more than 270 million tons of plastic debris in our oceans, and according to NOAA's Marine Debris Tracker, every year an additional 8 million metric tons are entering our oceans. That is the equivalent weight of 90 Nimitz Class aircraft carriers every year, and wreaks havoc on marine ecosystems. Damage to those ecosystems has devastating cascading effects for human life, most immediate of which is the negative impact on the primary protein sources for a large swath of the world's population. At this pace, it is estimated that by 2050 there will be more plastic trash in our oceans than fish.
WHERE DOES THE WASTE COME FROM?
In June 2018, the World Economic Forum cited a study by the Helmholtz Center for Environmental Research showing that 90% of the world's plastic waste in oceans comes from just 10 rivers: 8 in Asia, and 2 in Africa. The worst-polluting is the Yangtze in China. The Yangtze drainage is home to about half a billion people, where much plastic industry exists, and the Yangtze alone dumps more than 1.5 million tons of plastic into the East China sea. The Pearl, another Chinese river that is near the industrial area of Guangzhou, is also a top-10 river for volume of plastic waste.
According to the widely-read Jambeck Study released in 2015, Europe and North America make up less than 5% of plastic waste that enters the ocean, largely because what isn't incinerated or recycled locally is typically sent to landfills and is unlikely to make it into rivers.
However, this isn't about pointing fingers to the East. For years, the West has shipped 70% of its plastic waste to China for recycling. The total amount? Seven million tons per year, according to a report by NPR in 2019. Clearly shipping that amount of plastic waste to China helps North America and Europe avoid dealing with its plastic waste locally. And according to the 2015 Jambeck Study, the US itself is still responsible for about 121,000 tons of plastic waste entering the oceans yearly, as well (the equivalent of about 1.25x the weight of an aircraft carrier). Further, in a 2019 study from the Proceedings of the National Academy of Sciences (PNAS), there has been a rapid increase in plastic bottles in the South Atlantic Ocean, indicating major debris inputs from ships simply dumping waste by the ton directly into the ocean. This is new evidence that the large plastic waste islands floating in the world's oceans, which have caused so much worry among the population, are largely the result of how our waste is treated once it leaves our shores. Chinese recycling firms were purchasing shiploads of it to use as raw materials for manufacturing, and disposing of whatever they couldn't use. But, regardless of whether Western citizens feel duped about how it was being managed by Chinese waste and recycling firms, there is no avoiding that much of it is still waste that comes from us.
In the shadow of many of these studies, China has announced it will dramatically restrict waste dumping in its rivers, and will now refuse almost all of its trash and recycling imports. A leader in China's Ministry of Ecology and Environment was quoted in The Independent, a UK newspaper, that since this crack-down on river-dumping the amount of trash in the seas near China has actually spiked 27% because many are simply toting their trash out to the ocean instead of dumping it in China's rivers.
Clearly, more needs to be done to improve China's management of waste. But that aside, this almost total shut-down on China imports of waste has shut off the conveyor belt of recycling materials from West to East, and has caused North American and European waste management companies to scramble. American companies are now left to debate what to do with the loads of plastic waste they are collecting from US cities, which are now piling up at home.
HOW SHOULD WE DEAL WITH IT AT HOME?
America has nowhere near sufficient recycling capacity to recycle its own plastic waste today. This author has seen first-hand the process by which US firms have recycled their own plastic scrap, and has met in-person with manufacturing firms in the industrial regions of China. US capacity for recycling should be increased. But that will take time, and sorting recyclables remains a largely manual effort (and thus, difficult to sustain economically in the US). Because we can no longer assume that simply shipping our waste to China solves the problem, then reducing (more so than recycling) becomes the greater imperative.
But reduction alone won't solve our waste problem. There is an obvious (yet controversial) answer for dealing with the increase in onshore waste to manage in the US: Perhaps simply burying waste is not such a bad thing.
According to the Environmental Protection Agency (EPA), gases released via decomposition in municipal solid waste (msw) landfills are responsible for more than 15% of all human-related methane emissions in the US, and the EPA cites a study indicating that methane is up to 36x more powerful at trapping heat in the atmosphere than CO2 is. The EPA proposes that, instead of escaping into the air, landfill gas (LFG) can and should be captured, converted, and used as a renewable energy source. It can be done in a fairly straightforward process of burying landfills and cutting landfill gas wells into the buried waste for methane to be captured and piped for treatment and distribution (diagram below from epa.gov).
This will increase the need for more landfills, and in examining the locations of landfills throughout the US, many are clustered near the population centers on the coasts and the midwestern states so that they are within driving distance of the waste collection trucks. But anyone who has driven the wide expanses of the Mountain West has seen that available land is plentiful, especially in states such as Wyoming which covers 62 million acres, only 0.3% of which is for the incorporated towns that house close to 70% of the state's population.
For example, an enterprising firm in Wyoming might think to acquire land near the sparsely-populated areas long the freight rail lines that run through the state, and begin a brisk business of taking waste from the coasts and turning it into closed landfills that produce clean energy. Use that clean energy to power recycling plants near the firm (Oregon-based Agilyx has found a method of recycling soiled plastics and styrofoam using an oxygen-free melting process). Then sell the plastic pellets and raw materials produced back into industry. According to a Congressional Budget Office study released in March 2015, the cost of shipping freight via rail is only $0.05 per ton-mile (less than a third the cost of using trucks on the road). However, sorting continues to be an issue and plastics that do end up in landfills typically require 10-100 years to decompose. But PNAS announced in a 2018 study that an enzyme discovered by Japanese researchers that comes from bacteria (Ideonella sakaiensis 201-F6) can speed plastic decomposition to a matter of weeks. Apply this enzyme to plastic waste, and the landfills become more than just containment. They become an effective means of disposal.
A THREE-PRONGED APPROACH
After long and difficult effort, the US population has finally come to understand the importance of recycling, has adopted better habits, and instituted collection systems. That progress would be a terrible thing to abandon. But, our faith in offshore management of our recyclables is badly shaken. Instead of giving up, disillusioned, perhaps we can explore the idea of pointing the conveyor belt inward so it can be managed where we can better control the result.
- LANDFILLS: Find new locations for buried, closed landfills that are near freight rail lines. Then build LFG capturing systems to turn methane into clean energy.
- RECYCLING: Keep the public's focus on recycling. Use the energy from LFG processing at buried landfills to power nearby recycling plants. Use enzymes to speed the decomposition of plastics that can't/aren't recycled.
- REDUCTION: Increase the US public's awareness that we have to deal with our waste at home. That means we do not have unlimited space and time to manage it. So let us improve our efforts at reducing the plastics we use, and reusing what we can't eliminate.
It now appears that shipping our recyclables to China was largely a hold-me-over while the American public grew the will to change behaviors at scale. Now that the conveyor belt of trash to the East is dramatically restricted, it is time for us to build a scalable method of managing it at home. We have the land in the US to manage it, far from where it might end up in oceans. Landfill gas capture and re-use is one great tool in making this largely a net-positive, and recent discoveries around plastic decomposition and oxygen-free recycling make plastic waste management a potentially work-able cycle. We owe it to ourselves, and to the ocean, to try.